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PatchSiren cyber security CVE debrief

CVE-2024-35950 Siemens CVE debrief

A race condition vulnerability exists in the Linux kernel's Direct Rendering Manager (DRM) client subsystem. The flaw involves incomplete protection of display modes using the dev->mode_config.mutex lock, potentially allowing a local attacker with low privileges to exploit the race condition for confidentiality, integrity, and availability impacts. The vulnerability affects Siemens SIMATIC S7-1500 TM MFP industrial control systems through their GNU/Linux subsystem. CISA published this advisory on April 9, 2024, with subsequent updates through September 2025 adding numerous related CVEs to the same advisory. No patch is currently available from the vendor.

Vendor
Siemens
Product
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2024-05-20
Original CVE updated
2026-08-04
Advisory published
2024-05-20
Advisory updated
2026-08-04

Who should care

Industrial control system operators, OT security teams, and organizations deploying Siemens SIMATIC S7-1500 TM MFP systems with activated GNU/Linux subsystems should prioritize this vulnerability. The local attack vector requires attacker access to the device's interactive shell, making physical or remote shell access controls critical. Organizations in critical infrastructure sectors should apply CISA's defense-in-depth recommendations while awaiting vendor patches.

Technical summary

The vulnerability exists in the Linux kernel's DRM (Direct Rendering Manager) client implementation where display modes are not fully protected by the dev->mode_config.mutex lock. This race condition can be triggered by a local attacker with low privileges, potentially leading to use of uninitialized resources. The attack complexity is rated HIGH due to timing requirements, but successful exploitation yields HIGH impact on confidentiality, integrity, and availability. The flaw is particularly relevant in industrial environments where the Siemens SIMATIC S7-1500 TM MFP's GNU/Linux subsystem provides extended functionality beyond standard PLC operations.

Defensive priority

HIGH

Recommended defensive actions

  • Restrict interactive shell access to the GNU/Linux subsystem to trusted personnel only
  • Build and run applications exclusively from trusted sources
  • Monitor for vendor security updates from Siemens
  • Apply defense-in-depth strategies for industrial control systems per CISA guidance
  • Segment affected systems from untrusted networks where possible

Evidence notes

The vulnerability description indicates a race condition in DRM client mode protection (CWE-908: Use of Uninitialized Resource). CVSS 3.1 vector AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H confirms local attack vector with high attack complexity, requiring low privileges but no user interaction, with high impacts across confidentiality, integrity, and availability.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-35950 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-35950

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2024-35950 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-35950

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2024/icsa-24-102-01.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-265688.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-265688.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-24-102-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-alerts/ics-alert-10-301-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/resources-tools/resources/ics-recommended-practices

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/topics/industrial-control-systems

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf

    Reference

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.